This invention relates to mold pins and in particular to optic or reflex pins having means thereon to space them from adjacent pins when a plurality of the pins are grouped in an pin master or mold matrix.
While the invention is applicable to either optic pins or reflex pins used in a mold matrix, a reflex pin or pins are used as examples only and the specification is not limited only to that form of pin.
A pin master or matrix comprises a plurality of mold pins, for example reflex pins or a combination of optic pins and reflex pins, which are assembled into a specific configuration. The matrix (as it will be referred to hereinafter) is used to produce an electroform, by electrodeposition, or other suitable means, and the electroform so produced is then used to manufacture a mold which receives suitable mold material, such as thermoplastic, under pressure for making lens and/or reflective devices such as automobile lamp assemblies.
The outer lens portion of automotive lamp assemblies include sections made up of reflex elements, the purpose of which is to reflect light from an exterior light source directed at the lamp assembly. The reflex portion of a lamp assembly provides the reflective brilliance to a light source directed at the assembly i.e. from the headlights of a vehicle which are being directed at a rear lamp assembly incorporating the reflex elements. The brilliance of the reflective elements must meet standards set by various countries.
Lamp assemblies and their lenses for automotive vehicles are relatively simple to manufacture when the areas of the vehicles on which they are mounted are relatively flat. However, bodies of automotive vehicles are now smoothly contoured both on rear surfaces as well as front surfaces thereof in order to reduce the coefficient of drag and it has become more difficult to manufacture suitable lenses that will blend into these contours and which will still provide the required amount of reflectivity and brilliance required by law.
There is also a requirement for single, unitary lenses to meet the above mentioned needs for vehicles having smoother, rounded styling but which can also be tailored to the specific functions of the lamp assembly for a particular vehicle. For example, to meet safety requirements of certain countries, lamp assemblies must have lenses that extend into portions of the side surfaces of the vehicle as well as surfaces to the front and rear thereof. There are often compound curvatures to the surfaces to which the lenses must match.
One example of an automotive vehicle lens using reflex elements is shown in Canadian Patent 2,060,703 issued Oct. 17, 1995 to DBM Reflex Enterprises Inc. This patent illustrates a lens which has a combination of optical elements and reflex elements.
Conventionally, reflex elements, sometimes in combination with optical elements, are manufactured by assembling a large plurality of mold pins (reflex and if necessary optical pins) into a matrix and an electroform is then made by electro-depositing metal on the shaped ends of the mold pins in the matrix and then using the resulting electroform in a mold where plastic material is injected to form the reflected surfaces.
It is important in the preparation of a matrix to have the pins oriented properly to provide the directional brilliance and reflectivity in the finished product and it is therefore necessary, in the manufacturer of a reflective matrix, to ensure that the required reflectivity in the finished product is not lost in the curved portion thereof while matching the contour of a vehicle body.
There are several examples of arranging reflex pins in a bundle or matrix so that they provide the reflective brilliance in the resulting lenses, taking into account the above mentioned body contours of vehicles to which the lenses are attached.
One example of an attempt to meeting the requirements is shown in U.S. Pat. No. 4,733,946 of Mar. 29, 1988 to Cossetti. In this publication, reflex pins are machined such that their side surfaces are tapered towards the face of the matrix so that when the elements are grouped in a matrix, the tapered pins will provide the necessary curvature. However, while this may be effective, it is a very time consuming and very expensive manner in dealing with the problem.
In U.S. Pat. No. 5,565,221 of Oct. 15, 1996 assigned to DBM Reflex Enterprises Inc., the problem referred to above is addressed by providing spacers or wedges for use in combination with mold elements such as optic or reflex pins, in the pin master or matrix assembly. The spacers or wedges are selectively located between rows or banks of mold elements in the matrix to provide the required orientation to the optic and/or reflex pins. Thus the necessary reflective surfaces from the prisms will return the requirement amount of reflected light toward a source even when the surface of the product is on a contoured portion of a lamp assembly on a vehicle. The spacer consists of an elongated body having flat parallel side edges and converging faces which taper towards one another from a major edge to a minor edge. One of the faces has a surface profile to fit the profile of juxtaposed elements in the matrix assembly. These spacers or wedges do function well but problems have been encountered in bundling them in the matrix and maintaining the bundles with the elements in proper orientation.
Another example of the prior art is shown in the patent to Hedgewick U.S. Pat. No. 3,258,840 of Jul. 5, 1966.
The present invention addresses the problems referred to above by providing spacing means for use in combination with mold elements such as optic or reflex reflector pins, in the pin block or matrix assembly. The spacing means can be selectively located in producing a continuously variable pin axis electroform so as to alter the longitudinal axis of the pins relative to that of adjacent pins whereby the longitudinal axis of the pins are tapered with respect to one another towards the reflex ends of the pins.
In accordance with one broad aspect, the invention relates to a mold pin for use in a matrix in the production of a variable pin axis electroform, the pin having means thereon to effect variation in the longitudinal axis of the pin relative to that of adjacent pins in the matrix so that the longitudinal axis of the pins are tapered with respect to one another towards the operative ends thereof.
According to another broad aspect, the invention relates to a mold pin for use in a mold matrix where the pin has means to alter the longitudinal axis thereof relative to that of adjacent pins in the matrix so that the longitudinal axis of the pins are tapered with respect to one another toward the operative end of the pins. The axis altering means consists of a spacing member mounted on the pin at a location remote from the operative end thereof to space the remote location of the pin from adjacent pins in the matrix.
According to a still further aspect, the invention relates to the method of providing a mold pin with means for varying the longitudinal axis thereof relative to adjacent pins in a mold matrix. The method comprises the steps of (a) selecting a location on a sidewall of the pin; (b) drilling a socket in the side wall normal to the longitudinal axis of the pin; and (c) inserting a dowel in the socket whereby the dowel extends normal to the longitudinal axis of the pin and the length of protrusion of the dowel sets the degree of taper of the pin relative to an adjacent pin in the matrix.